Throughout this application various publications are referred to in parenthesis. Full citations for these references may be found at the end of the specification immediately preceding the claims. The disclosures of these publications are hereby incorporated by reference in their entireties into the subject application to more fully describe the art to which the subject application pertains.
Nuclear medicine involves the noninvasive quantification of physiological processes. In the case of positron emission tomography (PET), fluorine-18 deoxyglucose (FDG) has proven to be a remarkably good way of tracing the level of physiological glucose metabolism in living cells. Uptake of fluorine-18 deoxyglucose is proportional to the number of glucose transporter 1 (GLUT1) receptors expressed on the cell surface. The number of GLUT1 receptors on the surface is regulated by the cell in accord with its level of internally sensed demand for glucose. Once FDG glucose enters the cell, further metabolism is prevented by the lack of oxygen within the constructor. Thus, one has an ideal physiological tracer for glucose uptake, separated from further intracellular stages of glucose metabolism. New and improved PET scanners continue to be developed (e.g., Shiga et al., 2009).
Imaging studies have been used between groups of subjects to demonstrate evidence of injuries or pathologies (e.g., Kato et al., 2007; Zhang et al., 2010). Three dimensional images can be represented using voxels. A voxel is a data point on a regular grid in three dimensional space. A voxel, i.e., a volumetric pixel, is analogous to a pixel, which represents two dimensional image data. The data point can consist of a single piece of datum or multiple pieces of data. Voxel-based morphometry is an imaging analysis technique that can be used to investigate focal differences in, for example, the brain between two groups of subjects (e.g., Ashburner and Friston, 2000). Voxel-based morphometry studies have been carried out by comparing patients with controls, for example in studies of dementia (Mummery et al., 2000) and traumatic brain injury (Garcia-Panach et al., 2011).
The need for control groups can impede the use of imaging for diagnosis. This is especially the case since there are, for example, gender-specific cerebral areas of age-associated changes of FDG uptake (Kim et al., 2009). For example, accurate diagnosis of diffuse axonal injury is severely limited by requirements for adequate age- and gender-matched control groups. One widely used software program has only 4 patients below age 55; and only 37 patients in the 56-75 year age range as baseline controls. Other databases are even more lacking. Thus, it is impossible to objectively measure brain injury in those groups of individuals most prone to brain injury, i.e., infants, children, adolescents, athletes of age 15 to 30 and motor vehicle accident survivors aged 15 to 55. Data in those younger than 15 are very scarce.
The prevent invention address the need for a method of imaging injuries and pathologies that does not require comparison of a patient to a control group of subjects.